1. Field of the Invention
The present invention relates to a suspension board with circuit and, more particularly, to a suspension board with circuit used for a hard disc drive.
2. Description of the Prior Art
A suspension board with circuit used for a hard disc drive is a wired circuit board having a wiring circuit pattern which is integrally formed on a suspension board for supporting a magnetic head, for connection between the magnetic head and a read/write board. The suspension board with circuit is being in widespread use in recent years in that it can hold the magnetic head against an airflow generated when the magnetic head and the magnetic disk run relative to each other, while supporting the magnetic head closely spaced from the magnetic disc, to provide good flotation of the magnetic head.
This suspension board with circuit usually has at a front end portion thereof a gimbal portion comprising a tongue portion for mounting a magnetic-head mounting slider, and outrigger portions arranged at both widthwise sides of the tongue portion and forming the wiring circuit pattern thereon. In this configuration of the suspension board with circuit, rigidity of the outrigger portions plays a key factor for precise adjustment of the flotation (flotation angle) of the slider to the magnetic disc.
On the other hand, it also has for example the construction that an insulating layer of polyimide resin is formed on a substrate of stainless foil; a predetermined pattern circuit of a copper conductor layer is formed in a thin film form on the insulating layer; terminals are formed on the pattern circuit; and the whole surface of the pattern circuit, except the terminals, is covered with a cover layer, to protect the pattern circuit (e.g. JP Laid-open (Unexamined) Patent Publication No. Hei 10-265572).
Meanwhile, in accordance with miniaturization of the slider in recent years, further precise adjustment of the flotation (flotation angle) of the slider to the magnetic disc is being demanded.
However, since the outrigger portions of the suspension board with circuit, especially those designed for a small-sized slider, have high rigidity, it is hard to make a precise adjustment of the flotation (flotation angle).